Casein waterproof glue



Patented Feb. 2, 1926.

UNITED STATES 51L66 PATENT OFFICE.

I ANDREW A-. DUNHAM, OF BAINBRIDGE, NEW YORK, ASSIGNOR TO THE CASEIN MANU- FA'CTURING COMPANY, OF NEW YORK, Y., A CORPORATION OF VERMONT.

CASEIN WATERPROOF GLUE.

No Drawing.

T 0 all whom it may concern:

Be it known that 1, ANDREW A. DUNHAM, a citizen of the United States, and resident of Bainbridge, Chenango County, State of New York, have invented certain new and useful Improvements in Casein Waterproof G1ues, of which the following is a specification.

This" invention has for its object an improvement in casein water-proof glues;

which, when applied to wood, will prevent or minimize discoloration of the same.

The so-called Water-proof casein glues, as, is well known to those skilled in the art,

contain as their principal ingredients casein the pores of the wood to such an extent that the resulting product is unavailable for use in makmg articles in whlch the veneer is exposed to VlGW.

I have found that the staining or discolor-i. ing of the Wood is, to avery great degree, prevented by having finely ground wood,

fibre present in the glue. Although I do not claim that I can completely prevent discoloration, I can, by the means indicated, arrest, to a considerable extent. the tendency of the stain to penetrate thin veneers and appear on the outer surface. I prefer to use Wood-flour made from the hard woods such asbirch, beech and maple, although wood-flour made from other kinds of woods may be used if desired. from 5% to 20% by weight of wood-flour to from 95% to 80% of casein glue; I find that within these proportions there is little or no loss of strength in the glued joint, but on' the contrary in most cases I obtain added strength, probably because of the cohesion of the small particles of wood-flour with each other and with the interior sur faces of the pores of the woodlto be glued.

I prefer to use Application filed April 28, 1924. serial No. 709,688.

lVhile I may use less than 5% of Woodflour, I find that with this proportion the tendency of the stain to penetrate to the outer surface of the wood is more pronounced; and while I may use more than 20% of Wood-flour, I find that With this proportion the glue-is apt to lose its spreading qualities and that there is a decrease of strength in the resulting glued joint. For convenience of manufacture, I prefer to mix my wood-flour With the casein at the same time that the alkaline earth hydroxide and other chemicals are mixed therewith.-

The following examples will illustrate my invention:

Emample 1.

95 lbs. by weight of a casein water-proof i glue madeup in the proportions, byweight,

of 60% casein, 30% lime and 10% sodium carbonate are mixed with 5 lbs. of fine wood:

flour of the ordinary commercial grades.

This mixture is preferably made dry. The resulting glue base is then ready to be shipped to a veneer mill to be used in gluing Wood in the wellknown manner.

Ealample f2.

90 lbs..of the dry casein water-proof glue of the composition specified in example 1 are thoroughly mixed with 10 lbs. of 'ordi nary commercial finely ground wood-flour, The method of dissolving and applying th s glue is the usual one. well known to the art.

Ewa mple 3.-

80 lbs; of the casein water-proof glue of the composition specified under example 1 are mixed With 20 lbs. of ordinary commercial finely ground wood-flourm' After thorough mixing, the resulting material 'is ready to. pack and ship for use in the usual manner.

As casein water-proof glue is' marketed in water-proof glue I do not limit myself to any particular composition of a glue of this ready referred to other casein solvents such as carbonates, bicarbonates, phosphates, sulfites, silicates, fluorides and the like, and the amounts of the chemical or chemicals used with casein to make the glue may vary to a fairly large degree depending upon the quality of the casein used as Well as the particular work-for which the glue is to be employed, for instance, for the gluing of thick blocks of wood the composition of the glue may have to be different from that which is to be used for the gluing of veneer.

I claim:

As a composition 'of matter, a casein v water-proof glue having incorporated therewith from 5% to 20% by weight of woodflour substantially as and for the purpose described.

ANDREW-A. DUNHAM. 

